Thanks for your replies, there are sometimes cabs on ebay, but it is to expensive to ship to Europe. I want to build them, because I have the original components and it would be fine to hear them sounding like 60 years before. The volume of the cab is not the problem, you can find how wide,deep and high they are in some vott catalogs on ebay. The problem is the measurement of the horn, I only know, they have parallel flanges. Will look, maybe can see more on pictures.
Thank you, GST